Grinding machine



April 22, 1941. FLYGARE 2,239,091

' GRINDING MACHINE Fild April 5 1939 I 4 Sheets-Sheet 1 CA RL GFLYGARE April 22, 1941. Q FLYGARE 2,239,091

GRINDING MACHINE Filed April 5, 1939 4 Sheets-Sheet 2 :JI Wwvbdb CARI. G. FLYGARE I II 240" 254 280 253 I 5256 Z49 250 q 274 240 i 2 2 i 257 255 248 E 270 259 28] 52,? 5 240 26] i 263 Z61? j J April '22, 1941 Q FLYGARE Q 2239;091

GRINDING MACHINE Filed April 5, 1939 4 Sheets-Sheet 4 Patented Apr. 22, 1941 S PATENT OFFICE GRINDING MACHINE Carl G. Flygare, Worcester, Mass, assignor to Norton Company, Worcester, Mass., a corpora= tion of Massachusetts Application April 5, 1939, Serial No. 266,085

Claims.

thoroughly practical hydraulically stationary during a grinding operation and auto-,

matlcally indexed after each grinding operation to present a fresh grinding face. A further object of the invention is to provide a grinding wheel driving mechanism having an electrical time delay relay which serves to control the incremental indexing of the normally stationary wheel in timed relation with the wheel slide movement. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described, and the scope of'the application of which will be indicated in the following claims. 1

In the accompanying drawings in which is shown one of various possible embodiments of 1 the mechanical features of this invention,

Fig. 1 isan end elevation of a grinding machine having parts broken away and shown in section combined with a wiring diagram more clearly to show the operating construction;

Fig. 2 is a horizontal sectional View, on an enlarged scale, taken approximately on the line 2--2 of Fig. 1;

Fig. 3 is a horizontal sectional view, on an enlarged scale, taken approximately on the line 3-3 of Fig. 1; f

Fig. 4 is a vertical sectional view, on' an enlarged scale, taken approximately on the line 4-4 of Fig. 1;

Fig. 5 is a fragmentary sectional view taken.

approximately on the line 5-5 of Fig. 4;-

Fig. 6 is a fragmentary sectional view taken approximately on the line 6-6 of Fig. 4;

Fig. 'T-is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 1-1 of Fig. 1, showing the take-up mechanism for the chain drive;

, Fig. 8 is a fragmentary showing the mechanism for shifting the slow speed-high speed wheel driving clutch;

view, partly in section,

Fig. 9 is a fragmentary sectional view taken approximately on the line 9-9 of Fig. 3;

Fig. 10 is a fragmentary detail view taken approximately on the line ill-l0 of Fig. 2;

Fig. 11 is a fragmentary sectional view taken approximately on the line lI-ll of Fig. 3;

Fig. 12 is a fragmentary sectional view taken approximately on the line l2'--l2 of Fig. 4, showing a portion of thewheel spindle reciprocating or oscillating mechanism;

Fig. 13 is a fragmentary cross sectional view taken approximately on the line l3-l3 of Fig. 4;

Fig. 14 is a fragmentary sectional view taken approximately on the line l4-'-I4 of Fig. 4, showing the mechanism for adjusting the length of the reciprocatory stroke of the grinding wheel;

and i Fig. 15 15a fragmentary sectional view taken approximately on the line IS-l 5 of Fig. 2, showing a portion of the grinding wheel spindle reciprocating mechanism.

A grinding machine has been illustrated in the drawings comprising a base I0 which supports a transversely movable wheel slide H which 'is mounted on a V-way I2 and a flat way l3 on the base In. The wheel slide H supports a rotatable grinding wheel l5 which is mounted on one end of a rotatable wheel spindle IS. The spindle I6 is journalled in suitable bearings l1 and I8 within the wheel slide H. The right-hand end of the wheel spindle l6 (Fig. 4) is provided with a driving pulley l9 which is preferably of a multiple V-belt type. The wheel spindle It may be driven in a manner to be hereinafter described.

The base l0 also supports a longitudinally movable work table 25 which is arranged to recip rocate longitudinally relative to the base III on a flat way 26 and a V-way 21. The table 25 is provided with a rotatable work support including a headstock 28 and a footstock (not shown) each of which isv provided with work supporting centers rotatably to support a'work piece 29 in operative relation with the grinding wheel IS. The table 25 may be traversed longitudinally by a manually operable traversing mechanism which includes a rack bar 30 depending from the under side of the table 25. The rack bar 30 meshes with a gear 3| mounted on theinner end of a rotatable shaft 32. A manually operable traverse wheel 33 is'mounted on the outer end of the shaft 32 and is arranged to be manually rotated to traverse the table 25longitudinally relative to the base Hi. If desired, a power operated table traversing or reciprocating mechanism may be provided such as, for example, a mechanism of the type shown in the expired U. S. patent to Norton No. 762,838 dated June 14, 1904.

A wheel feeding mechanism is provided for manually feeding the grinding wheel I5 toward and from the work piece 29, which comprises a half nut depending from the wheel slide II.

The half nut 35 meshes with or engages a roon the outer end of the sleeve shaft 39 so that a manual rotation of thefeed wheel 41 serves to rotate the feed screw 36 in either direction to cause a forward or rearward feeding movement of the grinding wheel I5 and the wheel slide II. The feed wheel 4I may be provided with a micrometer adjusting mechanism 45 which is substantially identical with that shown in the above-mentioned prior U. S. patent to Norton. This micrometer mechanism serves precisely to adjust a stop abutment relative to the manually operable infeed wheel 4I so as to compensate for grinding wheel wear.

In the preferred construction the wheel slide II is arranged so that it may be moved toward and from the work piece 29 to grind the same to a predetermined size by means of a fluid pressure actuated wheel feeding mechanism. As

illustrated in the drawings, the rear end of the feed screw 36 is rotatably supported in a slidably keyed bearing 59 which is supported in a casing 51 integral with the base I9 of the machine. A fluid pressure cylinder 49 is attached to the casing H and contains a slidably mounted piston 52 which is connected by a piston rod 53 with the bearing 59 and is arranged so that when fluid under pressure is admitted to a cylinder chamber 54 the piston 52 will be moved toward the right (Fig. 1) into its rearward position, transmitting a corresponding movement through the feed screw 36 and the half nut 35 to move the wheel slide II and grinding wheel I5 rearwardly to an inoperative position.

Similarly, when fluid under pressure is ad mitted to a cylinder chamber 55, a rapid approaching movement of the grinding wheel I5 and the wheel slide II is obtained to. cause the grinding wheel to be moved into operative engagement with the work piece 29. A fluid pressure system is provided to supply fluid under pressure for moving the piston 52 so as to cause I an infeeding or outfeeding movement of the grinding wheel I5. This system may comprise a reservoir 69 which is formed as a box-like section within the base I9. A motor driven fluid pressure pump 6i draws fluid from the reservoir 69 through a pipe 62 and forces fluid under presvalve 64 is a piston type valve comprising a valve.

stem 65 having formed integrally therewith valve pistons 66, 61, 68 and 69. Fluid under pressure passing through the pipe 63 enters a valve chamber I9- located between the valve pistons I 61 and 66 and passes through a passage I2 into .the cylinder chamber 54 to move the piston 52 to its rearward position with the grinding wheel I5 separated from the work piece 29 as indicated in Fig. 1. During the rearward movement of the piston 52 that is toward the right (Fig. 1), fluid is exhausted from the cylinder chamber 55, through a passage 16, into a valve chamber I1 between the valve pistons 66 and 61, and out through a pipe 18 which exhausts into the reservoir 69.

Thevalve stem 65 is arranged so that it may be moved endwise to shift the valve 64 into a reverse position so as to cause either a forward or rearward feeding movement of the grinding wheel I5. In the preferred construction, the valve stem 55 extends toward the front of the machine base I9 and is supported at its forward end in a bearing 89 in the base I9. The outer end of the piston rod 65 is provided with a spoolshaped member 8| whichis'engaged by a stud 82 carried by a lever 63. The lever 83 is similarly mounted on a stud 84. A manually operable control lever 85 is supported on the stud 84 and is operatively connected to rock the lever 83 to shift the reverse valve 64 so as to produce either a forward or rearward movement of the grinding wheel I5.

A fluid pressure controlling or feed regulating mechanism is provided for modifying the rapid approaching movement caused by the piston 52 to obtain a controlled and predetermined infeed- 'ing movement of the grinding wheel I5. In the preferred construction a self-contained dash pot feed regulator is provided comprising a pair of dash pot cylinders 96 and 91 which contain dash pot pistons 99 and 99 respectively. The dash pot pistons 98 and 99 and their respective cylinders 96 and 91 are arranged with their axes parallel flange I94 is arranged to engage the right-hand I end faces of the dash pot pistons 98 and 99, respectively. The stop screw I92 engages the flange I94 and thereby serves to limit the rearward movement of the dash pot pistons 98 and 99 toward the right.

The rapid forward feeding movement of the grinding wheel I5 and wheel slide II continues until the adjustable nuts I95 on a threaded portion I96 of the piston rod 53 engage the righthand end of the sleeve I93. Continued movement of the piston rod 53 moves the sleeve I 93 and flange I94 toward the left (Fig. 1) and serves to move the dash pot pistons 98 and 99 in a direction toward the left. When the flange I94 engages the ends of the dash pot pistons 96 and 99, respectively, the rapid approaching or feeding movement of the grinding wheel I5 toward the work piece 29, as produced by the piston 52, is reduced to a slower predetermined grinding feed due to the fact that fluid confined within the dash pot cylinders 96 and 91, respectively, which are interconnected, exhausts through a passage I91, a needle valve I 96, through a pipe I 99, into a reservoir II9. By adjusting the aperture of the needle valve I98, a desired and predetermined infeeding movementof the grinding wheel I5 may be obtained. When fluid under pressure a rearward movement of the piston 52, the sleeve I03 together with the flange I04 is moved rearwardly by means of the released compression of the springs I and IM which returns the dash pot pistons 98 and 99, respectively, to their rearward positions and moves the flange I04 and its supporting sleeve I03 toward the right until the flange I04 engages the stop screw-I02. During the rearward movement of the dash pot pistons 98 and 99, a suction is created within the dash pot cylinders 96 and 91, respectively, which serves to aid in drawing fluid from the reservoir II0,

through a pipe III, and a ball check valve II2,

to fill the dash pot cylinder chambers 96 and 91 for the next infeeding movement of the grinding wheel I5. During the infeeding movement of the dash pot pistons 98 and 99, fluid within the dash pot cylinders 96 and 91 serves to hold the ball check valve II2 closed so that fluid Within the dash pot cylinders 96 and 91 is forced out through the passage I01 and the needle valve I08, into the reservoir II 0, to control the rate of infeeding movement, as desired. An adjustable throttle valve H1 is provided to facilitate the exhaust of fluid from the dash pot chambers 96 and 91 after the passage I01 is closed by the piston 98. If desired, the throttle valve II1 may beused to give a very fine final feed just prior to the stop I I3 engaging its stopping surface II4. In the latter case two distinct feeds of the grinding wheel II can be obtained, one feed by manipulation of the valve I08 combined with the opening of the valve II1 which continues until the passage I01 is cut oil, after which the infeed is reduced to a very slow infeed control by the throttle valve I I1.

- The forward feeding movement of the grinding Wheel I5 as controlled by the dash pot piston 98 and 99, respectively, continues until an adjustable stop collar H3 carried by the sleeve I03 engages a fixed stop surface II4 on the rear face of the dash pot cylinder head. A pair of lock collars II5 serve to position the stop collar H3 and to lock the same in adjusted position.

A throttle valve H6 is located in the pipe line 18 and serves to control the exhaust of fluid from the cylinder 49 so as to regulate the speed of movement of the grinding wheel I5 and its supporting wheel slide I I during the rapid approaching or positioning movement thereof.

.In order to obtain one of the objects of this invention, a grinding wheel driving mechanism is provided whereby the grinding wheel may be rotated at a normal grinding speed either for a grinding operation or for a truing operation, or the wheel may be rotated at a very slow speed below the normal grinding speed for a polishing operation, or the grinding wheel may be held against rotation for a honing operation and automatically indexed after each successive honing operation to present a new abrading face for the next operation.

The grinding wheel I5 is preferably driven by a motor driven mechanism comprising an electric motor I which is mounted on an adjustable support I3I. The adjustable support I3I is provided'wi'th a dovetailed slideway I32 which mates with a correspondingly shaped way on the top of a casing I33 which supports the gear driving mechanism. The casing I33'is adjustably mounted on the upper surface of the wheel slide II. The motor I30 is preferably a variable speed motor, such as a D. C. motor which receives its power from the power lines I34, As diagrammatically illustrated, a switch I35 serves to stop and start the motor I30, and a speed controlling device which is diagrammatically illustrated in Fig. 1 as a rheostat I36 serves to adjust and vary the speed of the motor I30, The motor I30 is provided with a driving pulley I31 which is connected by means of a multiple V-belt I38 with a multiple V- grooved pulley I39 which is mounted on the outer end of a shaft I40 which is journalled in a bearing MI in the casing I33. The inner end of the shaft, I40 is keyed within a sleeve 01'" bushing I42 which is in turn rotatably supported by antifriction bearings I43 which are supported by the casing I33. The sleeve I42 also supports a bearing bushing I 44 which serves as a bearing support for a rotatable shaft I45. The outer end of the shaft I 45 is journalled in a bearing I46 carried by the casing I33. A multiple V-grooved driving pulley I41 is mounted on the outer end of the shaft I45 and is connected by multiple V- belts I48 with the multiple V-grooved pulley l9 mounted on the outer end of the wheel spindle I6.

An adjusting screw I50 is rotatably supported in a bearing I5I which is either formed integrally with or fixedly mounted on the casing I33. The screw I50 is held against endwise movement relative to the bearing I5I and the screw I50 meshes with or engages a nut I52 depending from the under side of the motor support I3I, By adjusting the screw I50 the position of the motor mounting I3l may be adjusted so as to properly tension the driving belts I38. A similar screw I53 is rotatably supported against endwise movement in a bearing member I54 which is either formed integral with or fixedly mounted to the wheel slide II, The adjusting screw I53 meshes with or engages a nut I55 depending from the under side of the casing I33. By manipulation of the adjusting screw I53, the multiple V-b'elts I48 may be tensioned as desired.

In order to obtain a fast speed of the grinding wheel I5 for a normal grinding operation or for truing the grinding wheel, it is desirable to provide a suitable connection whereby the shaft -I40 may be connected directly with the shaft I 45. The slidably mounted clutch I is slidably keyed onto the shaft I45. The clutch I60 is moved toward the left (Figs. 2 and 3) so that the clutch teeth I6I of the slidably mounted clutch member I 60 engage clutch teeth I62 formed in the end of the rotatable sleeve I 42 which is keyed to the shaft I40 so that power is transmitted directly from the shaft I 40 to the shaft I45 and through the pulley I41 and multiple V-belts I48 to rotate the wheel spindle pulley I9, the wheel spindle I6, and the grinding. wheel I5 at a normal relatively fast grinding speed.

The clutch member I60 is preferably arranged so that it may be readily controlled from the op erators station in front of the machine. A yoked member I63 is supported on a rock shaft I64 which is journalled in bearings I65 and I66 in the housing or casing I33. The lower end of the yoked member I63 is provided with opposed studs or shoes I61 and I68 which ride in a groove I69 formed in the periphery of the clutch member I60, The shaft I64 is provided with agear segment I10 which meshes with a gear segment I1I carried by a shaft I12 which has one of its ends journalled in a bearing I13 formed in the casing I33 and has its outer end journalled in a bearing member I14 which is fixedly mounted on -a bracket fixedly mounted on the wheel slide II. The shaft I12 is free to slide longitudinally within the bearing I14 to facilitate transverse adjustment of the driving mechanism contained within the casing I33. The outer end of the shaft "2 is provided with a manually operable actuating handle I15. Formed integral with the gear segment member is a downwardly extending arm I18 which is'provided with a pair of apertures I11 and I18 which are arranged to be engaged by means-of a spring-pressed detent I19 to readily locate the gear segment I in one of two positions, namely with the clutch teeth I8I in engagement with the clutch teeth I62, or with clutch teeth I80 in engagement with clutch teeth I8I formed integral with a rotatable bushing I82 which forms a part of a slow speed driving mechanism to be hereinafter described. As shown in Figs. 2 and 3, the clutch I60 is in a slow speed position. If' it is desired to rotate the grinding wheel I5 at a rapid speed, that is the normal grinding or truing'speed, the manually operable control lever H5 is shifted from full line position '(Fig, 8) into broken line position I'I5a which rocks the gear segment III in a counterclockwise direction. This movement in turn rocks the gear segment I10, the shaft I84, and the yoked member I63 in a clockwise. direction to shift the clutch member I60 toward the left (Figs. 2, 3 and 8) so that the clutch teeth I5I eng e the clutch teeth 1I62 to form a direct driving connection between the shaft I40 and I45.

To facilitate rotation of the grinding wheel I5 at a very slow rotative speed below the normal grinding speed, the shaft I40 is provided with a worm I85 (Fig. 3) which meshes with a worm gear I86. The worm gear I86 is keyed to a transversely arranged rotatable shaft I8'I which is journalled in bearings I88 and I89 which are supported in the casing I33. The forward end of the shaft I81 is rotatably supported in a sleeve I90 which is in turn journalled in bearings I89 supported in the casing I33. A warm I9I is keyed to the rotatable bushing I90, said parts being arranged so that the worm I9I and its supporting bushing I90 may rotate independently of the shaft I8'I. The worm I9I meshes with a worm gear I92 which. is supported on a longitudinally extending shaft I93. The shaft I93 is journalled in bearings I94 and I95 supported in the casing I33. A sprocket I96 is keyed to the shaft I93 and is arranged to transmit its rotative power through a link chain I91 to a sprocket I98 which is keyed to the periphery of the rotatable sleeve I82. j

The worm I9I is" arranged so that it may be readily clutched or declutched from the shaft I81. A clutch member 200 is sildably keyed onto the shaft I87 and is provided with clutch teeth I which are arranged to engage clutch teeth 202 formed integrally on the end of the worm I9I. A yoked member 203 is supported on the end of a slidably mounted actuating rod 204. The rod 204 is journalled in a bearing 205 fixedly mounted relative to the casing I33. The yoked member 203 has integral shoes which-engage a groove 205 formed in the periphery of the clutch member 200 so that endwise movement of the rod 204 serves to throw the clutch teeth 20I into rod 204 may be actuated manually, if desired, or in the preferred construction, as shown in the drawings, a solenoid 209 is supported on a bracket 2I0 fixed on the rear of the casing I33. A solenoid armature 2 is connected by means of a link 2I2 with an arm 2I3 of a bell crank lever which is pivotally mounted on a stud 2I4 carried by the bracket 2I0. A downwardly extending arm 2I5 of the bell crank lever is formed as a. yoked member having downwardly extending arms which are connected by a stud 2I8 with one end of a link 219. The other end of the link 2I9 is connetced by a stud 220 which is in turn supported by the clutch shifting rod 204.

The spring 201 normally holds the clutch member 200 in a disengaged position. When the solenoid 209 is energized in a manner to be hereinafter described, the clutch member 200 will be engagement with the clutch teeth 202 so that thrown into an operative position with its clutch teeth 20I engaging the clutch teeth 202 formed on the end of the worm I9I to transmit a slow rotary motion through the mechanism above described to the shaft I45 and from there to the grinding wheel I5.

A stop screw 222 is supported in a threaded aperture in a boss 223 integral with the bracket 2I0. The screw 222 is arranged so that when the clutch shifting rod 204 is moved downwardly (Fig. 2) to throw the clutch 20I into engagement to rotate the worm I9I by means of the mechanism above described to rotate the grinding wheel I5 at a very slow rate of speed, the screw 222 may be screwed into position so that its end projects in back of the clutch shifting rod 204 so as to hold the clutch 200 in engagement and thus provide a continuous rotation of the grinding wheel I5 at a relatively slow speed below the -normal grinding speed. Forc'ertain types of abrading operations, such as the honing or finishing of a cylindrical work piece 29, it is proposed to provide a stationary grinding wheel I5 during the polishing, finishing or honing operation and to provide an indexing mechanism whereby after each grinding operation, the grinding wheel may be indexed a small angular distance so as to present, a fresh a-brading surface for the next operation. This is preferably accomplished by providing an automatic timed controlling mechanism for energizing and deepergizing the solenoid 209.

As illustrated in the drawings (Fig. 1), a normally open limit switch 230 is supported on a bracket 23I which is fixedly mounted on the rear of the dash pot speed control mechanism. An adjustable switch actuating member 232 is adjustably mounted on the end of the piston rod 53 and is arranged when the wheel I5 and its supporting slide II ismoved into a rearward or inoperative position to close an electric circuit receiving its source of power from power lines 233 to set in motion an electrically operated time delay relay 234' which serves to energize the solenoid 209 either the instant the switch 230 is closed or at a predetermined interval thereafter. The energizing of the solenoid 209 serves to engage the clutch teeth 20I with the clutch teeth 202 to rotate the reduction gear mechanism above described to rotate the grinding wheel I5 8. fraction of a turn to present a fresh abrading surface for the next grinding or finishing operation. The extent of indexing or rotary movement of the wheel I5 is controlled and governed by adjustment of the electrically actuated time delay relay 234 sothat the wheel I5 may be rotated only a small angular distance or a greater angular distance as desired by adjustment of the time interval setting of the electrically operated time delay relay 234. A switch 235 is provided to facilitate opening the circuit and rendering the entire electrical control mechanism inoperative when desired. A second electrical switch 236 is provided which serves to render the electric time delay relay 234 inoperatve so that when opened, a manually operable push button 231 which is located adjacent to the operator's control station on front of the machine base I8, may be utilized to instantaneously energize the solenoid 209 to facilitate angularly indexing the grinding wheel I when desired by the operator.

In either a plunge-cut grinding operation or a finishing operation where the grinding wheel I5 is held stationary or rotated at a very slow speed,

it is desirable to provide a grinding wheel spindle reciprocating mechanism whereby the grind- 7 ing wheel spindle I6 may be reciprocated in an axial direction withinits bearings I1 and I8. As illustrated in the drawings, a wheel spindle reciprocating mechanism is contained within a housing 248 which is mounted on the upper portion of the wheel slide II. An eccentric 24I is formed integral with a rotatable sleeve 242. The sleeve 242 is rotatably journalled in bearings 243 supported in the housing 240. The sleeve 242 is preferably drivingly connected with the shaft I81 by means of a key 244, thus forming a telescopic driving connection between the shaft I81 and the sleeve 242 which facilitates adjustment of the casing I33 in tensioning the grinding wheel driving belts I48. The eccentric 24I is connected by a connecting rod 245 with a stud 246 carried by an arm 241 which is pivotally supported on a fulcrum stud 248. A frame 249 which is substantially of a C-shaped cross section is formed integral with the arm 241 and is supported at its other end by a fulcrum stud 250. When the eccentric 24I is rotated by the shaft I81, an oscillating motion'will be transmitted by the connecting rod 245 to oscillate the arm 241 and the frame 249 about the fulcrum studs 248 and 250. The opposite sides of the C-shaped frame 249 are provided with substantially vertically extendthe length of the reciprocatory stroke of the wheel ing grooves 25I and 252 which support slide blocks 253 and 254, respectively. The slide blocks 254 support the trunnion ends 255 and 256 of a. reotangularly shaped block 251 which is slida-bly positioned within an elongated slot 258 in a rock arm 259. The rock arm 259 is pivotally supported on a shaft 260 which is journalled in suitable bearings within the wheel slide v II. The rock arm 259 is provided with an enlarged ring-shaped portion which surrounds the wheel spindle I6 and carries a ring-shaped member 26I which is provided with trunnions 262 and 263 which project into bearing apertures in diametrically opposite sides of the enlarged portion ofthe rock arm 259. The ring-shaped member 26I is suppor-tedbetween a fixed collar 265 and an adjustable thrust collar 266 carried by the wheel spindle I6 and serves to provide an end thrust bearing for the ring 26I, said parts being arranged so that when the lever or rock arm-259 is oscillated, a reciprocating movement is transmitted to move the wheel spindle I6 axially within its supporting bearings I1 and I8 to produce a reciprocatory movement of the grinding wheel I5 during an abrading, honing or finishing oper- 'ation.

It is desirable to provide means for adjusting trated in the drawings, a reciprocatory stroke varying from zero up to one-eighth of an inch or more may be obtained; A vertically movable yoke-shaped member 210 is vertically adjustable by means of a rotatable screw 21I-. The screw 2" is journalled in bearings which are fixedly supported in the housing 246. The upper end of the screw -21I is provided with a bevel gear 212 which meshes with a bevel gear 213 supported on the inner end of a rotatable shaft 214 the uter end of which is provided with a manually operable adjusting wheel 215. The vertically adjustable member 210 is provided with yoke-shaped arms 286 and 28I which surround anti-friction ball bearings which are supported on the trunnions 255 and 256 of the slide block 251. As the screw 21I is rotated, the member 210 will be moved vertically, which serves to adjust the slide block 251 relative to the elongated aperture 258 in the rock arm 259 and at the same time adjusts the slide blocks 253 and 254 relative to the grooves 25I and 252 in the substantially G-shaped frame 249 so that the axis of the trunnions 255 and 256, respectively, may be moved toward or from the axis of the trunnions 248 and 250, respectively, to vary the length of the reciprocatory stroke of the wheel spindle I6. As illustrated in the drawings, the wheel spindle reciprocating mechanism is shown as adjusted to its maximum extent. If it is desired to change the reciprocatory stroke, the screw 21I is adjusted to lower the adjustable member 218 which serves to lower the trunnions 255 and 256 so that they approach the axes of the trunnions 248 and 250, thereby reducing the oscillatory motion transmitted to the rock arm 259 and thus reducing the reciprocatory movement of the wheel spindle I6 and the grinding wheel I5. If the adjustable member 210 is lowered until theaxes of the trunnions 255 and 256 coincide with the axis of the trunnions 248 and 250, then no oscillating movement-will be transmitted to the rock arm 259 and the wheel spindle I6 will be held against reciprocatory chain I91, a bell crank lever 285 is pivotally mounted on a stud 286 within the casing I33. A horizontally extending portion 281' of the bell crank lever 285 has an upper curved face which bears against the under side of the link chain I91 between the sprockets I96 and I98. An adjusting screw 288 is screw threaded into the casing I33 and bears against a vertically extending arm 289 of the bell crank lever 285. By manipulation of the adjusting screw 288, the tension of the link driving chain I91 may be adjusted as desired.

The operation of this improved machine will be readily apparent from the foregoing disclosure. Assuming the various mechanisms and adjustments to have been previously made, the machine as illustrated in the drawings is set up.for a honing or finishing operation with a stationary grinding wheel I 5 which is automatically indexed when the wheel slide I I is moved to its rearward position automatically to present a fresh grinding face for the next operation. A work piece 29 is placed in position in the machine between centers and a starting switch 292 is closed to start the rotation of the work driving motor 293. A rheostat 294 is adjusted to vary the speed of the motor 293 so that the work 29 rotates at the desired speed. The switch I35 is then closed to start the rotation of the wheel driving motor I30.

The position of the parts illustrated does not start the rotation of the grinding wheel it since the wheel is normally held stationary but is rotated a small angular portion of one complete.

tinues until the desired flnish is obtained. If desired, an automatic cycle control mechanism may be provided to allow the grinding wheel l5 to remain in operative engagement with the work piece 29 for a predetermined time interval. However, such a mechanism is not considered to be a part of the present invention and consequently has not been illustrated. For details of such a cycle control mechanism, reference may be had to the U. S. patent to Goehring No. 2,151,660 dated March 21, 1939.

After the work piece 29 has been finished to the desired extent, the lever 85 is moved in a clockwise direction to again shift the feed control valve stem 65 into the position illustrated in Fig. 1. As the wheel slide I l approaches its rearmost position, the collar 232 carried by the threaded end portion of the piston rod 53 engages and closes the normally open limit switch 230 which operates to set the time delay relay 234 in operation. Substantially instantaneous with the starting of the time delay relay 234, the solenoid 209 is energized which serves to rock the bell crank lever 2 i3 and thereby shift the clutch shifting rod 204 downwardly (Fig. 2) to engage the clutch teeth 2M of the clutch 200 with the clutch teeth 202 on the end of the worm I 9|, thus starting rotation of the grinding wheel IS. The electrical time delay relay 2 is set for a very short interval so that the grinding wheel i5 moves only a few degrees of one rotation so as to present a fresh abrading surface for the next operation. As soon as the time delay relay 234 functions, the circuit is again opened to .deenergize the solenoid 209,'thereby releasing the compression of the spring 201 which moves the clutch, shifting rod 204 upwardly (Fig. 2) to disengage the clutch teeth 2! from the clutch teeth 202, thus stopping the rotation of the grinding wheel l5 after it has indexed a desired number of degrees so as to present a fresh abrading surface for the next honing or finishing operation. The amount of indexing movement may be varied as desired, but due to the fact that the operation is a cylindrical grinding. operation utilizing the periphery of an abrasive wheel, only a very small indexing movement is required to present a fresh abrading surface for finishing the next work piece 29. This cycle of events then continues as desired.

If it is desired to rotate the grinding wheel l5 at a normal grinding speed for a grinding operation or for truing the grinding wheel, the clutch 200 is held in a normal disengaged position and the lever H5 is rocked into the broken line position li5a (Fig. 8) which serves to slide the clutch member I68 so that the teeth iBi engage the teeth I62 formed in the end of the rotatable sleeve M2 so that the driving shaft Mt is connected directly to the driven shaft I45 to rotate the wheel spindle I6 and the grinding wheel II at a normal grinding speed for a grinding operation or a truing operation. v

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that alh matters he'relnabove set forth or shown in the accompanying drawings is to be interpreted as illustrative andnot in a limitingsense.

I claim:

1. In a grinding machine having a longitudinally movable .work table and a transversely movable wheel slide, a rotatable work support on said table, a rotatable grinding wheel on said slide, means to feed said wheel slide and work support relatively-toward and from each other,

said grinding wheel being normally held stationary during a, grinding operation, an indexing I table, a normally-stationary rotatably-mounted grinding wheel on said slide, means to feed said slide toward and from said work support to produce an abrading operation, an electrically actuated indexing. mechanism rotatably to index said grinding wheel a partial rotation to present a new abrasive surface, and means including an electrical control device which is actuated by the wheel slide when it moves to an inoperative position to, actuate said indexing mechanism so as to present a new abrasive surface for the next grinding operation.

3. In a grinding machine having a longitudinally movable table and a transversely movable wheel slide, a rotatable work support on said table, a feeding mechanism to move said slide transversely toward and from said work support to produce an abrading operation, a normallystationary rotatably-mounted grinding wheel on said slide, and an electrically controlled indexing mechanism including an electrical time delay relay which is rendered operative by and in timed relation with the rearward movement of said wheel slide automatically to index said grinding wheel a partial rotation to present a new abrading surface for successive grinding operations.

4. In a grinding machine having a longitudinally movable work table and a. transversely movable wheel slide, a rotatable work support on said table, a feeding mechanism to feed said wheel slide transversely toward and from said work support, a normally-stationary rotatablymounted abrasive wheel on said slide, a. driving mechanism including an electric motor for rotating the grinding wheel, an indexing mechanism including an automatically controlled clutch to connect and disconnect said. driving mechanism, electrically controlled means including a solenoid to actuate said clutch, and means including an electrical time delay relay which is set in motion by and in timed relation with said wheel slide movement to energize said solenoid for a predetermined time interval so as to index the grinding wheel and present a new abrasive surface for successive grinding operations.

5. In a grinding machine having a longitudinally movable work table and a transversely movable wheel slide, a rotatable work support on said table, a feeding mechanism to feed said slide transversely toward and from said work support to produce an abrading operation, a normallystationary rotatably-mounted grinding wheel on said slide, a driving mechanism including a variable speed electric motor to rotate said grinding wheel at a slow rate of speed, means including a clutch to connect and disconnect said driving mechanism with the wheel, means including a solenoid to actuate said clutch, an electrically operated time delay relay which is operatively connected to energize said solenoid for a predetermined time interval, and a switch which is actuated by the feeding mechanism when the wheel slide is moved rearwardly after an abrading operation rotatably to index the grinding wheel to present a new abrading surface for the succeeding grinding operation.

6. In a cylindrical grinding machine having a longitudinally movable table and a transversely movable wheel slide, a rotatable work support on said table, means including a variable speed electric motor to rotate a work piece supported thereon, a rotatable grinding wheel, means including a variable speed electric motor to rotate said grinding wheel, driving connections between said motor and wheel whereby the grinding I wheel may be rotated either at a normal grinding speed or at a slow speed below the normal grinding speed or held stationary for a finishing or polishing operation, and means automatically actuated 'to rotatably index said wheel after each finishing or polishing apparatus to present a new abrading surface for the next operation. 7. In a cylindrical grinding machine having a longitudinally movable table and a transversely movable wheel slide, a rotatable work support on said table, means including an electric motor to rotate a work piece supported thereon, a rotatable grinding wheel, means including an electric motor to rotate said grinding wheel, driving connections between said motor and wheel whereby the wheel may be rotated at a normal grinding speed, driving connections between said motor and wheel whereby the wheel may be rotated at a slow speed below the normal grinding speed. said latter mechanism being arranged to hold said grinding wheel stationary for a finishing operation, and means automatically actuated rotatably to index said wheel after each finishing operation. I

8. In a cylindrical grinding machine having a longitudinally movable table and a transversely movable wheel slide, a rotatable work support on said table, means including a variable speed motor to rotate a work piece supported thereon, a rotatable grinding wheel, means including a variable speed electric motor to rotate said grinding wheel, driving connections between said motor and wheel whereby the wheel may be rotated at a normal grinding speed, driving connections between said motor and wheel whereby the wheel may be rotated at a slow speed below the normal grinding speed, said latter mechanism being arranged to hold said grinding wheel stationary for a finishing operation, and means automatically actuated to rotatably index said wheel after each finishing operation.

9. In a cylindrical grinding machine having a longitudinally movable table and a transversely movable wheel slide, a rotatable work support on said table, means including a variable speed electric motor to rotate a work piece supported thereon, a feeding mechanism to feed said wheel slide transversely toward and from said table, a rotatable grinding wheel supported on said wheel slide, a driving mechanism whereby said wheel may be rotated at a slow speed below the normal grinding speed, said driving mechanism being arranged to hold said grinding wheel stationary for a polishing or finishing operation, and an indexing mechanism which is actuated by and in timed relation with said wheel slide to rotatably index said grinding wheel after a polishing operation 'to present a new abrading surface for the next operation.

10. In a cylindrical grinding machine having a longitudinally movable table and a transversely movable wheel slide, a rotatable work support on said table, means including an electric motor to rotate a work piece supported thereon, means to traverse said table longitudinally, a rotatable grinding wheel supported on said wheel slide, means to feed said wheel slide and grinding wheel transversely toward and from said work support, means including a variable speed electric motor to rotate said grinding wheel at a slow speed below the normal grinding speed, said latter mechanism being arranged to hold said grinding wheel stationary for a polishing or finishing operation, and an electrically controlled indexing mechanism which is actuated in timed relation with said wheel slide movement rotatably to index said grinding wheel after each grinding operation to present a new abrading surface for the next operation.

CARL G. FLYGARE. 

